NEW YORK, June 10 (Reuters) - U.S. stocks eased on Tuesday after the Dow and S&P 500 hit a string of record highs, though high-growth momentum stocks mostly advanced.

The day’s losses were slight but broad, with eight of the 10 primary S&P 500 sector indexes down for the day. The S&P industrials index, the biggest decliner, was down just 0.4 percent.

Momentum stocks, marked by hyper levels of growth and concerns about valuation, ranked among the day’s biggest outperformers, with a number of Internet names also up for the day. Facebook Inc rose 4.3 percent to $65.59. Netflix Inc gained 1.4 percent to $429.11.

Shares of eBay fell 2.2 percent to $48.51 after news late Monday that David Marcus, who has led eBay’s fast-growing payments unit PayPal for the past two years, will step down this month to run Facebook’s messaging products.

Tuesday’s decline comes after a string of gains for Wall Street. The S&P 500 has closed at a record for the past four sessions, and ended higher 11 times in the past 13 sessions.

“Most valuation metrics suggest that equities are no longer cheap, though they’re not exactly overpriced where they are now. People are looking for reasons to really buy, but we’re optimistic that equities can continue to push higher,” said David Carter, chief investment officer of Lenox Wealth Advisors in New York.

Trading volume, which has been below average of late, continues to make the market more susceptible to big swings. The CBOE Volatility index declined 2 percent and remains at very low levels from a historical perspective.

Achillion Pharmaceuticals Inc was among the Nasdaq’s most-active names, surging 60 percent to $6.80 in brisk trading, building on a jump of almost 48 percent on Monday. The company said on Tuesday that the U.S. Food and Drug Administration allowed it to resume the development of one of its hepatitis C drugs. JMP Securities upgraded the stock to “market outperform” from “market perform.”

Biotech stocks also got a lift from Receptos Inc, which jumped 35.5 percent to $39.57 after the company’s experimental multiple sclerosis drug met its main goal in a mid-stage trial.

RadioShack Corp slid 12.3 percent to $1.35 after the U.S. electronics retailer reported a much wider-than-expected quarterly loss.

Chico’s FAS Inc shares jumped 7.8 percent to $16.57 in heavy trading after the Financial Times reported that the women’s apparel retailer was exploring a sale to private equity. (Additional reporting by Ryan Vlastelica; Editing by Nick Zieminski, Bernadette Baum and Jan Paschal)